Creamy Tomato Soup with Grilled Cheese Croutons

Dice the onion finely and mince the garlic cloves.

In a large pot, melt 2 tablespoons of butter with the olive oil over medium heat. Add the diced onion and cook for 4 to 5 minutes until soft and golden.

Add the minced garlic and cook for 30 seconds until fragrant. Pour in the canned crushed tomatoes, sugar, and salt. If using spinach, add it now. Stir well and bring to a simmer. Cook for 12 to 15 minutes, stirring occasionally.

While the soup simmers, make the grilled cheese croutons: butter both sides of 2 slices of bread. Place sliced mozzarella between the bread slices. Cook in a skillet over medium heat for 2 to 3 minutes per side until golden and the cheese is melted.

Remove the grilled cheese from the skillet and let it cool for 1 minute, then cut into 1-inch cubes to create the croutons.

Remove the soup from heat. Using an immersion blender (or working in batches with a regular blender), puree the soup until completely smooth and velvety.

Return the pureed soup to low heat. Stir in the milk and the remaining tablespoon of butter. Heat through for 2 minutes without boiling. Taste and adjust seasoning with additional salt or sugar as needed.

Ladle the hot soup into bowls and float the grilled cheese croutons on top. Serve immediately while the croutons are still crispy on the outside and gooey on the inside.